Fig. 3: Reversibility experiments.

a–d, Final steady-state grounding lines (a,c) and flowline profiles (b,d) for model simulations with different thermocline depths. e, Flowline grounding-line position as a function of thermocline depth for each model simulation. Upward pointing triangles indicate the final grounding-line position for simulations that start at the subglacial ridge in the retreat group. Downward pointing triangles indicate the final grounding-line position for simulations that start at the upstream ice plain position in the advance group. The advance simulations all start from the final grounding-line position from the last retreat simulation (11 km along flowline). The open black and red triangles indicate the grounding-line position from the control (700 m) and warm (600 m) transient experiments, respectively, that were shown in Fig. 1. Note the solid black lines between markers in e are not results of model runs but are for visual purposes only. The grey shaded region in e corresponds to steep retrograde sections of bed, which are also indicated by black dash-dotted lines in all panels. The ___location of the flowline is shown as a dash-dotted line in a and c.